There are several means of prevention against HTTP buffer overflow attacks:
1. Input Validation: This is the most effective method of preventing buffer overflow attacks. Input validation includes checking the length of the input data, ensuring that the input data is in the correct format (e.g. alphanumeric characters), and restricting the number of characters that can be entered.
1. Compiler-Based Protections: A compiler can be configured to automatically add security checks to the code to prevent buffer overflow attacks. For example, some compilers will add stack canaries to the code to prevent buffer overflows.
1. Address Space Layout Randomization: Address space layout randomization is a technique that randomly arranges the memory layout of a program, making it more difficult for attackers to predict the location of the buffer.
1. Data Execution Prevention: Data execution prevention (DEP) is a technique that prevents programs from executing code from memory areas that are intended to store data. This can help prevent buffer overflow attacks that involve executing malicious code from a buffer.
1. Operating System Protections: Operating systems can provide additional protections against buffer overflow attacks. For example, Windows includes a feature called Structured Exception Handling (SEH) that can help prevent buffer overflow attacks.
Overall, a combination of these techniques can significantly reduce the risk of buffer overflow attacks. However, it is important to note that no single technique can provide perfect protection against all types of buffer overflow attacks.
